function updateDescription () {
	id_department = $("#id_department").val (); 
	/* 3 th 
	* id_department ==0 la k lam gi 
	* isNaN (id_department) == true la truong hop phai login moi dc post department
	* nguoc lai
	*/
	$(".departments .inline-infos").fadeOut (1000);
	$(".descripton_department").fadeOut (1000);
	$(".post-ticket").fadeOut (1500);
	$(".login-department").fadeOut (1500);
	
	if (isNaN(id_department)==true){
		var arr=id_department.split("_"); 
		id_department= arr[0];
		$(".descripton_department").fadeIn (1500);
		$("#department_"+id_department).fadeIn (1500);
		$(".login-department").fadeIn (1500);
	}
	else if (id_department!=0) {
		$("#department_"+id_department).fadeIn (1500);
		$(".descripton_department").fadeIn (1500);
		$(".post-ticket").fadeIn (1500);
		$(".login-department").fadeOut (1500);
	}
	else {
		$(".departments .inline-infos").fadeOut (1000);
		$(".descripton_department").fadeOut (1000);
		$(".post-ticket").fadeOut (1500);
		$(".login-department").fadeOut (1500);
	}
	$('.confimComplete').fadeOut (5000);
}
